In JP 2003-313533 A, an invention relating to an anisotropic electroconductive adhesive containing a urethane acrylate resin and organic peroxides is described. In the anisotropic electroconductive adhesive according to the corresponding invention, in addition to a phenoxy resin, an acrylic resin elastomer is contained as an essential component, and they are added so as to be used as a film forming agent for forming them into a film shape and to exhibit a toughness property of the film. A phosphoric acid ester compound with specific structure is also added to exhibit the effect as a coupling agent. Furthermore, the anisotropic electroconductive adhesive according to the corresponding invention has a constitution in which the adhesive is obtained by having electroconductive particles dispersed in the adhesive resin composition.
Furthermore, from the viewpoint that the aforementioned invention relates to an anisotropic electroconductive adhesive, a constitution of having an absolutely small addition amount of electroconductive particles is postulated, and such constitution is different from so-called silver paste added with a large amount of electroconductive particles (isotropic electroconductive adhesive) significantly in terms of the addition amount of electroconductive particles. Herein, it is known that, as the addition amount of electroconductive particles increases in a electroconductive adhesive, the addition amount of resin components decreases to yield a tendency of having faster speed at which viscosity of adhesive increases due to significant reflection of a change in viscosity of the resin components. It is also known that, although the apparent speed at which viscosity increases may be suppressed by using a solvent, use of a solvent tends to cause a decrease in adhesive strength or poor outer appearance due to foaming in a cured product as caused by solvent volatilization during curing.